Avalanche Forecast

Issued: Jan 13th, 2013 9:20AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs.

Avalanche Canada ghelgeson, Avalanche Canada

Email

Kootenay Boundary.

Increasing hazard is tied directly to the forecasted warm up, which may not happen until Wednesday in this region. See the forecasters blog for some ideas about the changing situation.

Summary

Confidence

Poor - Freezing levels are uncertain on Tuesday

Weather Forecast

Monday:  Mod/Strong W/NW winds at ridgetop.  Freezing level at valley bottom.  No significant snowfall.Tuesday:  Warm air dominates the regions to the north, but it should remain cool in the Kootenay Boundary region.  Mod/Strong W/NW winds at ridgetop.Wednesday: Cold air remains in the valleys, temperatures between 1000m & 2500m rise as warm as +5c.

Avalanche Summary

No new significant avalanche observations, just reports of sluffing from steep terrain and small shallow skier controlled soft slabs.

Snowpack Summary

10 cm of light density snow fell Thursday adding to the 60 cm of rapidly settling storm snow that rests on the January 4th interface which consists of small facets, surface hoar (up to 12mm) in sheltered treeline and below treeline areas and sun crust on steep south and west facing slopes. The bonds at this interface are improving.  The layer is still alive and well in test pits but has not been reactive to human triggering in the last day or so.  Wind slabs created by the previously raucous SW winds have grown old & tired. The midpack is well bonded and strong. The November 28 surface hoar is still being found in isolated, sheltered below treeline locations buried 120cm. The deep crust/facet combo from early November still exists but seams to have gone dormant for the time being.

Problems

Persistent Slabs

An icon showing Persistent Slabs
The 50 - 100 cm of storm snow has settled out nicely and the while likelihood of triggering has greatly decreased I suspect it's still possible to trigger an avalanche failing on the Jan. 4th interface in terrain that is steep rocky and/or convex.
Stay cautious with open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>While recently inactive, rapid warming and solar radiation is coming our way Wednesday which will weaken the snow surface, possibly triggering an avalanche on the surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Jan 14th, 2013 2:00PM

Login
Join